Device for closing molds of an injection molding machine

Abstract

A device for closing molds of an injection molding machine for plastic which includes a stationary end plate and a mold clamping plate displaceable on traverses. The stationary end plate is connected to the clamping plate by a toggle mechanism having a double toggle lever. The double toggle lever is actuatable by at least two drive units arranged between the end plate and the mold clamping plate, parallel to a main axis of the machine.

I claim: 
     
       1. A device for closing molds of an injection molding machine for plastic having a main axis, comprising: a stationary end plate;   a mold clamping plate;   a plurality of traverses mounted to said stationary end plate and extending toward said mold clamping plate, said mold clamping plate being displaceably guided along said traverses;   a double toggle lever, having a central portion, a first end connected to said stationary end plate and a second end connected to said mold clamping plate;   a crosshead; and   at least two drive units, between said end plate and said mold clamping plate, connected to said crosshead and mounted at said end plate and having an axis of displacement parallel to the main axis of the machine, said drive units being linked in form locked manner via said crosshead to said central portion of said double toggle lever for lever movement of said central portion with respect to said end plate such that said mold clamping plate is displaced along said traverses.   
     
     
       2. The device according to claim 1, wherein said crosshead is linked to said double toggle lever by an articulated lever arm. 
     
     
       3. The device according to claim 1, wherein said crosshead comprises a torsionally rigid framework. 
     
     
       4. The device according to claim 3, further comprising a guide bearing arranged on said crosshead for guiding movement of crosshead parallel to the main axis of the machine. 
     
     
       5. The device according to claim 4, further comprising a guide bar fastened to said stationary end plate and extending toward said crosshead, wherein said guide bearing is displaceably mounted on said guide bar. 
     
     
       6. The device according to claim 4, wherein said guide bearing is displaceably mounted on said traverses. 
     
     
       7. The device according to claim 1, wherein said drive units comprise hydraulic piston-cylinder units. 
     
     
       8. The device according to claim 7, wherein said piston-cylinder units include differential cylinders. 
     
     
       9. The device according to claim 8, further comprising a cylinder of said piston-cylinder units and a travel surface provided on said cylinder of the piston-cylinder units. 
     
     
       10. The device according to claim 8, wherein said end plate includes a housing part comprising a guide for directing a movement of said travel surface. 
     
     
       11. The device according to claim 7, wherein said piston-cylinder units comprise synchronous cylinders. 
     
     
       12. The device according to claim 11, further a housing part of said stationary end plate and comprising piston rods of said synchronous cylinders, wherein said piston rods are fastened at both ends to said housing part. 
     
     
       13. The device according to claim 1, wherein said drive unit comprises a rotatably driven ball screw. 
     
     
       14. The device according to claim 1, further comprising a mechanical stop provided on said stationary end plate for limiting a range of displacement of said drive units. 
     
     
       15. The device according to claim 14, further comprising a shock absorber arranged on said stop for reducing impact forces. 
     
     
       16. The device according to claim 14, wherein said stop comprises an axially displaceable adjustment for adjusting a range of displacement of said drive units. 
     
     
       17. The device according to claim 4, wherein said guide bearing comprises a plurality of guide bearings, each arranged on said crosshead for guiding movement of crosshead parallel to the main axis of the machine. 
     
     
       18. The device according to claim 17, wherein said guide bar comprises a plurality guide bars fastened to said stationary end plate and extending toward said crosshead, wherein said guide bearings are displaceably mounted on said guide bars. 
     
     
       19. The device according to claim 17, wherein said guide bearings are displaceably mounted on at least two of said traverses.